Air-cooled internal combustion engine



J. A. EQUCHEQZI AIR COOLED INTERNAL COMBUSTIONENGINE Filed Sept. 18,1951 Fig -L 26 Patented 17, 1934 UNITED STATES AIB-COOLED IN'I'E RNALCOMBUSTION GINE Joseph A. Boucher, Jr., Bridgeport, Comm, as-

signor of one-third Bridgeport, Conn.

to D. Lewis Mattern,

Application September 18, 1931, Serial No. 563,559

15 Claims.

The present invention relates to an improved air-cooled internalcombustion engine, and has for an object to provide a construction whichwill be light in weight. simple and .economical to manufacture, andreliable and cilicient in operation.

It is particularly proposed to provide a series of cooling fins arrangedin spaced and stacked relation upon the cylinder block, each fin beingcommon to the entire block, and being perforated in a manner to draw theheat generated in the en- 'gine away from the cylinders, and to rapidlyand efiectually dissipate it. It is further proposed to construct thefins of a metal, such as cast aluminum, which will be light in weightand which because of its porous nature will rapidly dissipate heat.Another object is to provide cooling fins which will maintainsubstantially uniform efficiency along the entire length of the engine,and to this end I propose to gradually diverge the fins from front torear, so that the air will remain in contact with the fins as itpasses'along the engine and will not trail off'toward the last cylinder.

With the above and other objects in view, embodiments of my inventionare shown in the accompanying drawing, and these embodiments will behereinafter more fully described with reference thereto, and theinvention will be finally pointed out in the claims.

In the drawing:

Fig. 1 is a side elevation, partly in vertical section showing anexemplary-embodiment of my invention incorporated in a four cylinderinternal combustion engine.

Fig. 2 is a front end view thereof.

Fig. 3 is a horizontal sectional view taken along the line 3-3 of Mg. 1.

Fig. 4 is an edge view of one of the fins.

Fig. 5 is a vertical sectional view of a modified form of the inventionas applied to the cylinder of radial type of engine.

Fig. 6 is a top view thereof.

Fig. 7 is a sectional View taken along the line 7-7 of Fig. 5.

Similar reference characters indicate .corresponding parts throughoutthe several figures of the drawing.

Referring to the drawing, the invention, according to the exemplaryembodiment illustrated W herein, is incorporated in a four cylinderinternal combustion engine comprising a crank case 10 to which the baseof the cylinder block is suitably secured, this block comprising aplurality of cylinders l1, l2, l3 and 14 connected by vertical 55centrally disposed webs l5, l6 and 17. The cylinder heads 18 in whichthe exhaust and inlet valves 19 and 20 are arranged is preferably castintegral with the cylinders, as is also the exhaust and inlet manifoldstructure 21 above which latter W the housing 22 for the valve operatingmechanism lid 23 is mounted. Spark plugs 24, preferably two to eachcylinder are provided in the cylinder heads. While I have shown aparticular type of engine it will be understood that I do not wish to belimited in this respect, and may incorporate my invention in anysuitable type of engine.

The engine block is preferably cast of semisteel or other suitablematerial which p ssesses sufiicient strength and lightness for theproduction of relatively thin walled cylinders.

Near the base of the cylinders there are provided vertical ribs 25 uponthe shouldered upper ends of which the fins are adapted to be supported,as will presently more fully appear.

The fins 26 are concentric at their front and rear ends to the front andrear cylinders and the side edges diverge from the front to the rear, so

that the fin is of gradually increasing area toward the rear. An opening27 conforming to the outline of the cylinder block is provided in thefin, and lugs 28 are cast upon the upper surface preferably in line withthe ribs 25 of the cylinder block, these lugs serving as spacers andsupports for the superimposed fins which are stacked upon the cylinderblock. Perforations 29 of gradually increasing diameters toward the rearare pro-- vided in the fins, the larger perforate area toward the rearbeing substantially proportionate to the increase in width of the finand the tendency of the heat to build up toward the rear as it passesrearwardly along the cylinders.

As shown in Figs. 1 and 2 the fins are stacked. upon the cylinder blockin spaced relation, being supported upon the shouldered ribs 25 andsecured by a top fin 30, preferably imperforate and formed ofsemi-steel, or other suitable material, and brazed to the cylinder head,as at 31. As before pointed out the fins are preferably formed of castaluminum, which has the desired characteristics of lightness andstrength, and which due to its porous nature is particularly efficaciousin drawing and dissipating heat.

The large perforate area of the fins is such that the heat of the enginecylinders is drawn to thesev perforations, and the air rushing betweenthe fins rapidly dissipates it. Due to the diverging shape of the finsthe air will not trail ofi near the rear cylinders but will remain inrelation to the fins in sufiicient volume to dissipate the heat until itpasses beyond the last cylinder.

The cylinders are preferably fired in reverse order, that is the No. 1cylinder will be fired in the rear instead of in front, so that the heatof the No. 1 cylinder immediately passes off without passing over theother cylinders. When the No. 4 cylinder in front fires the heat passesover the entire motor, so that a substantial uniformity of temperatureis maintained throughout the cylinders.

In Figs. 5 to 7 I have illustrated a modified Ill) form of theinvention, incorporated in a radial type engine, one cylinder 32 ofwhich is shown in1"i8.5. Asintheilrst embodimentthefins33 are concentricto the cylinder at the front and rear and diverge toward the rear andhave an opening 34 for enga the cylinder. Perforations 35 are providedof increasing size toward the rear, and spacing and supporting lugs 36are formed adjacent the opening 34. The head 37 of the cylinder and thetop securing fin 38 are preferably provided with radial flns 39.

I have illustrated and described preferred and satisfactory embodimentsof my invention,- but it will be obvious that changes may be madetherein within the spirit and scope thereof as defined in the appendedclaims.

Having thus described my invention what I claim and desire to secure byLetters Patent is:-

1. In an air-cooled engine, a cylinder, and a series of perforatedseparately formed plates stacked exteriorly upon said cylinder insuperimposed and spaced relation to each other, the perforation of saidplates beingof increasing size from front to rear.

2. In an air-cooled engine, a cylinder, and a series of perforatedseparately formed plates stacked exteriorly upon said cylinder insuperimposed and spaced relation to each other, the side edges of saidplates diverging from front to rear and said perforations being ofincreasing size from front to rear.

3. In an air-cooled engine, a plurality of in-line cylinders, and aplurality of perforated fins exteriorly of said cylinder in superimposedand spaced relation to each other, each in being common to a pluralityof said cylinders, the perforations of said plates being of increasingsize from front to rear.

4. In an air-cooled engine, a plurality of in-line cylinders, and aplurality of perforated separately formed plates stacked exteriorly uponsaid cylinder in superimposed and spaced relation to each other, eachplate being common to a plurality of said cylinders and having aplurality of openings adapted to be respectively engaged by saidcylinders, the side edges of said plates diverging from front to rear.

5. In an air-cooled engine, a plurality of inline cylinders, and aplurality of perforated separately formed plates stacked exteriorly uponsaid cylinder in superimposed and spaced relatlon to each other, eachplate being common to a plurality of said cylinders and having aplurality of openings adapted to be respectively engaged by saidcylinders, the perforation of said plates being of increasing size fromfront to rear.

6. In an air-cooled engine, a plurality of inline cylinders, andaplurality of perforated separately formed plates stacked exteriorlyupon said cylinder in'superlmposed and spaced relation to each other,each plate being common to a plurality of said cylinders and having aplurality of openings adapted to be respectively enled by saidcylinders, the side edges of said plates diverging from front to rearand said per- I foratlons being of increasing size from front to gagedby said cylinders, the lateral area of said plates increasing from frontto rear.

8. In an air-cooled engine, a plurality of inline cylinders, a pluralityof perforated separately formed plates stacked exteriorly upon saidcylinders in superimposed and spaced relation to each other, each platebeing common to a plurality of said cylinders and having a plurality ofopenings adapted to be respectively engaged by said cylinders, the sideedges of said plates diverging from front to rear.

9. In an air-cooled engine, a plurality of inline cylinders, and aplurality of perforated fins exteriorly of said cylinders insuperimposed and spaced relation to each other, each fin being common toa plurality of said cylinders, the side edges of said fins divergingfrom front to rear.

10. In an air-cooled engine, a plurality of inline cylinders, and aplurality of perforated plates arranged exteriorly of said cylinders insuperimposed and spaced relation to each other, each plate being commonto a plurality of said cylinders and having a plurality of openingsadapted to be respectively engaged by said cylinders, the side edges ofsaid plates diverging from front to rear.

11. In an air-cooled engine, a plurality of inline cylinders, and aplurality of perforated plates arranged exteriorly of said cylinders insuperimposed and spaced relation to each other, each plate being commonto a plurality of said cylinders and having a plurality of openingsadapted to be respectively engaged by said cylinders, the perforationsof said plates being of increasing size from front to rear.

12. In an air-cooled engine, a cylinder, a series of perforated plateshaving a cylinder engaging opening and stacked exteriorly upon saidcylinder in superimposed relation, and a plurality of spacing meanscarried by said plates contiguous to said cylinder engaging opening andin spaced relation about said opening and adapted to support and spacesaid plates relative to each other, said spacing means being contiguousto said cylinder whereby air cannot pass between said spacing means andthe cylinder, and the cylinder wall being exposed circumferentially ateach side of said spacing means.

13. In an air-cooled engine, a cylinder, and a series of perforatedseparately formed plates stacked exteriorly upon said cylinder insuperimposed and spaced relation to each other, the side edges of saidplates diverging at each side from front to rear and to a pointrearwardly of the transverse diameter of said cylinder, wherebythelateral area of said plates increases from front to rear.

14. In an air-cooled engine, a cylinder, and a series of perforatedseparately formed plates stacked exteriorly upon said cylinder insuperimposed and spaced relation to each other, said plates being ofincreasing width from front to rear and to a point rearwardly of thetransverse diameter of said cylinder whereby the lateral area of saidplates increases from front to rear.

15. In an air-cooled engine, a plurality of inline cylinders, and aplurality of perforated fins exterlorly of said cylinders insuperimposed and spaced relation to each other, each plate being commonto a plurality of said cylinders, the side edges of said platesdiverging from front to rear, and the perforation of said plates beingof ina ing size from front to rear.

JOSEPH A. BOUCHER, Js.

